By the way, mate tea itself tastes quite good and that's what people should drink. Club-Mate on the other hand tastes terrible and not so much like mate tea at all, imo.
I agree that the taste takes some getting used to. There's a reason the unofficial slogan is "Man gewöhnt sich d'ran" ("One gets used to it"). For me it's mostly the high caffeine content alongside a comparatively low sugar content (lower than any other energy drinks or other caffeinated soft drinks I've come across -- except for the "sugar free" ones).
I tried sugar-free energy drinks for a while but I find the taste too jarring to get used to. I still drink sugar-free Red Bull on occasion (and actually prefer it to regular Red Bull) but I couldn't stand relying on it as my primary source of caffeine.
Basically, Club Mate is my coffee. Red Bull is my espresso. I don't drink coffee (I can't stand the small) but I think that comparison probably works best.
EDIT: Just noticed the article says the slogan "Man gewöhnt sich d'ran" is on the bottle. That seems wrong. I've never seen the slogan used officially. I always thought it was coined by its users, not the company itself.
I haven't come across that particular slogan, though.
For reference, here's a few German beverages and official slogans:
Afri-Cola: "Liebt einander und werdet durstig" / "Love each other and get thirsty" (1999)
Bionade: "Das offizielle Getränk einer besseren Welt" / "The official beverage of a better world" (2007)
Astra (beer): "Was dagegen?" / "Do you mind?" (1998)
Fritz-Kola: "Vielviel Koffein" / "Muchmuch caffeine" [sic!] (2006)
Bluna: "Sind wir nicht alle ein bisschen Bluna?" / "Aren't we all a bit Bluna?" (1995)
This is a correct but too innocent translation. "Liebt einander" can both be translated to love each other and also to make love. The latter leads to:
Make love and get thirsty.
I am sure the ambiguity was intended.
More serious: I don't remember anyone but Afri really trying to be 'special'. Not that hard. I'm ignoring all the weirdo energy drinks in cans for now..
2015:
* "Vater rolle": "father roll" (same pun as in English: "father role" would be "Vaterrolle" (no space))
* "Such das Kölsch": "Find the Kölsch"
* "Dosiert feiern": "Dosed partying" ("Dose" also means "can")
2014:
* "Da haben wir die Bescherung": "There we have the mess" ("Bescherung" literally means the handing out of presents on Christmas)
* "Vom Weltmeister empfohlen": "Recommended by the (football) world champion"
* "Früh Sport mit Poldi": "Früh Sport with Poldi" (Poldi refers to football player Lukas Podolksi, "Früh Sport" could also be read as "Frühsport", which means "morning workout")
* "Ist ja schließlich nicht Muttertag": "After all it's not Mother's Day." (a lot of father's day customs involve getting drunk)
* "Karneval nicht irgendwas aufreißen": "Not tearing up just anything on Karneval" ("Karneval" refers to Rhineland carnival, "tear something/someone up" also has the same notations of "picking someone up" -- i.e. finding a date or getting lucky)
* "So hätte jeder gehandelt": "Everyone would have done it this way"
2013:
* "Fließend Kölsch": "Fluent/Running Kölsch" ("fließend" here is a pun as it can either refer to the beer pouring from a tap or fluency in the Cologne dialect also called Kölsch)
* "Das gelbe vom Ei": "The yellow of the egg" (common phrase meaning "the best part of something")
* "... Mutters Tag": "... mother's day" ("Mother's Day" is called Muttertag in German, so this is meant to be read literally)
* "Vaters Tag ...": "Father's day ..." (same deal as above)
* "Leider geil!": "Unfortunately horny/awesome!" (meaning something to the effect of "I'm afraid to say this is totally awesome", hook-line of a popular German rap song that was getting a lot of radio play time at the time)
* "Wechselwähler": "Swing voter"
* "Heilige Drei Könige": "Holy Three Kings" (referring to the Three Wise Men / Kings of the East in the Christmas story; Cologne Cathedral has a shrine that allegedly carries the remnants of the Three Wise Men)
2012:
* "Alles andere ist Fasching": "Everything else is carnival" ("Fasching" is a term for German carnival used in various German-speaking regions other than the Rhineland; in the Rhineland it is called "Karneval")
* "Kleinste Theke der Welt": "Smallest bar in the world" (Düsseldorf has a downtown area that is often called "Längste Theke der Welt", i.e. "largest bar in the world"; Düsseldorf and Cologne have a long-standing (today mostly humorous) rivalry)
* "Es löwt weiter": "It's carrying on" (the correct phrase would have been "Es läuft weiter", "löwt" sounds similar enough but is a reference to Jogi Löw, the trainer of the German national football team)
* "Wir sind mit dem Radler da": "We are here with the Radler" ("Radler" is a popular shandy consisting of lemonade and beer; it's likely derived from "Fahrrad", meaning "bicycle": a "Radler" is someone who "radelt", i.e. someone who uses a bike)
* "Gefällt mir": "Like" (literally "I like this"; this is what the Facebook "Like" button reads in Germany)
* "Heilig am Abend": "Holy in the evening" (a play on "Heilig Abend": "holy night", the night before Christmas)
I'm not going to do the rest, though ;)
I don't quite understand why people always bring up genuine mate tea in these discussions on HN. As you say, it's a completely different thing. Club Mate is what you drink instead of cola for an alternative flavor and more caffeine.